Effects of pH and cultivation time on the formation of styrene and volatile compounds by penicillium expansum

Hye Won Kim, Sang Mi Lee, Jeong Ah Seo, Young Suk Kim

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7 Scopus citations


Styrene can be formed by the microbial metabolism of bacteria and fungi. In our previous study, styrene was determined as a spoilage marker of Fuji apples decayed by Penicillium expansum, which is responsible for postharvest diseases. In the present study, P. expansum was cultivated in potato dextrose broth added with phenylalanine-which is a precursor of styrene-using different initial pH values and cultivation times. Volatile compounds were extracted and analyzed using gas chromatography-mass spectrometry (GC-MS) combined with stir-bar sorptive extraction. The 76 detected volatile compounds included 3-methylbutan-1-ol, 3-methyl butanal, oct-1-en-3-ol, geosmin, nonanal, hexanal, and decalactone. In particular, the formation of 10 volatile compounds derived from phenylalanine (including styrene and 2-phenylethanol) showed different patterns according to pH and the cultivation time. Partial least square-discriminant analysis (PLS-DA) plots indicated that the volatile compounds were affected more by pH than by the cultivation time. These results indicated that an acidic pH enhances the formation of styrene and that pH could be a critical factor in the production of styrene by P. expansum. This is the first study to analyze volatile compounds produced by P. expansum according to pH and cultivation time and to determine their effects on the formation of styrene.

Original languageEnglish
Article number1333
Issue number7
StatePublished - 2019

Bibliographical note

Publisher Copyright:
© 2019 by the authors.


  • Cultivation time
  • Penicillium expansum
  • Phenylalanine metabolism
  • Styrene
  • Volatile compounds
  • pH


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